This invention relates to a method for complexing metal oxide particles in an organic medium as well as to a method for dispersing or flocculating metal oxide particles in an organic medium. This invention also relates to a magnetic recording medium comprising a magnetic carrier and an improved magnetizable coating provided on said carrier.
Many end use applications require that certain metal oxide particles be complexed to achieve a desired effect such as dispersing the particles in an organic medium. For example, in the recording industry, in order to achieve a useful magnetizable coating on a non-magnetic carrier, it is necessary to finely disperse magnetic pigments in a carrier by means of a binder. Also, in the plastics industry, it is often necessary to uniformly disperse throughout a plastic an amount of a finely divided metal oxide such as antimony trioxide or antimony pentoxide. In order to achieve uniform stable dispersions of such metal oxides in organic media, it is necessary to utilize an effective amount of a complexing agent which in that application functions as dispersing agent. Dispersing agents which have been used in the past include, for example, N-acylsarcosine derivatives, as taught in U.S. Pat. No. 4,153,754. Also, for purposes similar to that disclosed in the aforementioned patent, it is known to use compounds such as N-tallow-1,3-diamino propane, especially in the form of its dioleate salt.
An object of the present invention is to provide improved complexing agents for use in dispersing or flocculating finely divided metal oxide particles in organic media.
The foregoing and other objects will become apparent from the following description of the invention.